A man who was allegedly viewing pornographic cartoons in a North Side library told police he hadn't registered as a child sex offender because he doesn't have an address. He has one now: Cook County Jail.

Police were called to the Chicago Public Library, 929 W. Buena Ave. in the Buena Park neighborhood, Saturday afternoon because patrons had seen John Cameron, 60, allegedly looking up child pornography on a computer there, according to police.

When he saw police, Cameron, who was sitting at terminal No. 8, "immediately clicked off" the computer before speaking with officers outside. Investigators found the site he'd been visiting had pornographic cartoons and video games on it, but no photographs, police said.

When officers asked him for identification, Cameron told police he was John H. Farmer, of the 4500 block of North Broadway, police said. He appeared nervous and told police he had cannabis in his backpack, police said. Officers also found a state identification card with his real name and address — the 5200 block of North Ashland Avenue, police said.

While he was being booked, officers found he is a child sex offender who has not registered. When asked why, police said, Cameron replied: "I tried to register but they wouldn't let me because I don't have an address."

Cameron was charged with one felony count of failing to register as a child sex offender and possession of cannabis, according to a spokeswoman for the Cook County Court Clerk's office.

Cameron was booked into Cook County Jail Monday after a judge set a $150,000 bail, according to the Cook County Sheriff's office.

According to the Illinois Sex Offender's website, he was convicted in Grundy County of aggravated criminal sexual assault, aggravated criminal sexual assault of a victim who is age 13 or under, and loitering with 500 feet of a park. He was 37 at the time, according to the website.